The Gospel Oak Study stage II: the diagnosis of dementia in the community

Abstract

SynopsisAn attempt was made to assess in detail subjects screened as suffering from dementia among a North London community sample of elderly people. Forty-eight (80 %) subjects were interviewed, 7 (12%) were found to have died and 5 (8%) either refused interview or were lost to follow-up. By clinicians' diagnosis of the 48 interviewed, 22 subjects (46%) had probable Alzheimer's disease, one had multi-infarct dementia, five had mixed dementia, five had secondary dementia, 10 had a dementia which could not be further classified and 5 were not demented. No subject had a reversible condition. The prevalence rate for clinical dementia was 6·1 %, and for Alzheimer's disease 3·1 %. According to AGECAT diagnosis the prevalence of organicity was 5·7%. The AGECAT diagnoses and psychiatrists' diagnoses were significantly associated (P < 0·003) and AGECAT was more likely to identify as organic those subjects with dementia diagnosed by psychiatrists as Alzheimer's disease, than those not so diagnosed (P < 0·04). A short psychometric battery, including the MMSE in two versions, was administered and its acceptability to a community sample evaluated. This detailed clinical investigation showed that the Dementia Diagnostic Scale of the Short-CARE was a specific predictor of clinical dementia or death at the time of follow-up, whereas the more inclusive Organic Brain Syndrome scale was a more satisfactory first phase screening instrument.